Comparison of angle, length, and diameter of the eustachian tube of safe and unsafe CSOM based on CT scan in Dr. Zainoel Abidin General Hospital, Banda Aceh, Indonesia

Abstract

Introduction: Damages in middle ear structures correlated with tubal dysfunction and impaired drainage; thus, it's associated with changes in angle, length, and tubal diameter. This study aimed to determine the ratio of angle, length, and diameter of Eustachian tube with safe and unsafe types of chronic suppurative otitis media (CSOM).Methods: Cross sectional analytical retrospective design, CT-Scan assessment for angle, length, the diameter of the tube on safe and unsafe type CSOM from January to December 2019 Angle is assessed using Reid's line, tube length by a tympanic orifice to pharyngeal orifice line, Tube diameter is measured from anteroposterior pre-tympanic line diameter. Results: From 61 CSOM patients, 70.5% safe type, 29.5% unsafe type. Safe type tube angle mean is 29.120, unsafe type 29.950, normal ear 28.230, thus no significant difference. A significant difference in the tube length (P = 0.001) is that the mean normal ear is 35.39 mm, smaller on safe type 33.58 mm, and unsafe type 29.53 mm. A significant difference in tubal diameter ratio (P = 0.001), normal diameter 2.19 mm, on safe type is 2.02 mm smaller, unsafe type 1.86 mm.Conclusion: The smaller length and diameter of the Eustachian tube will lead to unsafe type CSOM.